1. Field of the Invention
The present invention relates to access network performance prediction and, more particularly, to a method and apparatus for predicting access bandwidth on an xDSL network.
2. Description of the Related Art
Data communication networks may include various computers, servers, nodes, routers, switches, hubs, proxies, and other devices coupled to and configured to pass data to one another. These devices will be referred to herein as “network devices.” Data is communicated through the data communication network by passing data packets (or cells, frames, or segments) between the network devices by utilizing one or more communication links. A particular packet may be handled by multiple network devices and cross multiple communication links as it travels between its source and its destination over the network.
Consumers seeking to access a data communication network, such as the Internet, may utilize several technologies, such as a modem, cable modem, ISDN, Digital Subscriber Line (DSL) technology, or other conventional technologies. Several DSL technologies offer high-bandwidth services over existing twisted pair copper telephone wires commonly referred to as “subscriber loops.” Such technologies include Asymmetrical DSL (ADSL), High-bit-rate DSL (HDSL), Rate Adaptive DSL (RDSL), Symmetric DSL (SDSL), and Very high speed DSL (VDSL). These, and other DSL-based technologies, will be referred to herein collectively as xDSL.
The bandwidth available over xDSL to a subscriber will vary depending on many factors, such as the distance between the subscriber and the central office (the terminating point on the provider side), the type of equipment deployed at the central office, other physical characteristics of the subscriber loop, and disturbers to the subscriber loop. A telecommunications company seeking to provide xDSL service to a subscriber may desire to obtain an estimate of likely bandwidths that it may be able to provide to the subscriber on a particular loop, depending on different xDSL deployment strategies (i.e. different inside wiring strategies and DSLAM configurations). Estimating the maximum bandwidth and other parameters associated with xDSL service on that loop may be used to enable the telecommunications provider to set correct expectations with the subscribers, and sell the correct service to the subscribers.
Several methods of estimating bandwidth on a subscriber loop have been proposed. One such method is disclosed in Liu, et al., (U.S. Pat. No. 6,266,395, entitled SINGLE-ENDED SUBSCRIBER LOOP QUALIFICATION FOR XDSL SERVICE) the content of which is hereby incorporated by reference. Liu, et al. disclose a method of providing a bandwidth estimate based on physical characteristics of the subscriber loop such as length, conductor size, cable insulation type, and the type of devices and services installed on the subscriber loop. Although Liu, et al. is able to get a good estimate, it would be advantageous to increase the accuracy to provide better estimates of likely available bandwidth for new xDSL subscribers.